I think death has some actual benefits. Yes, some of our comfort with death comes with learning to live with its inevitability, but it has genuinely some upsides. I think they have some to do with being able to change things and institutions, but mostly it centers around our brains and psychology. Our life cycle is connected to how our brain develops and matures, inherently I think.

For example, if you go through some events in your childhood, they may stick with you until your death, as an inevitable part of you. Sure, treatment helps, but probably some memories you can't just erase.

Recycling things into a next generation, with probably better living conditions seems like generally pretty positive thing.

Also, some time you'd probably start to stop learning, not necessarily due to brain aging and neuron death, but simply because of basic architecture of our brain and how information solidifies and it starts to become more difficult to learn new things. We are a little more bored of most things and a lot of mystery and wonder diminishes somewhat.